Abstract
This review article was designed to evaluate the existing evidence related to the molecular processes of SARS-CoV-2 infection in the oral cavity. The World Health Organization stated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and transmission is produced by respiratory droplets and aerosols from the oral cavity of infected patients. The oral cavity structures, keratinized and non-keratinized mucosa, and salivary glands’ epithelia express SARS-CoV-2 entry and transmission factors, especially angiotensin converting enzyme Type 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). Replication of the virus in cells leads to local and systemic infection spread, and cellular damage is associated with clinical signs and symptoms of the disease in the oral cavity. Saliva, both the cellular and acellular fractions, holds the virus particles and contributes to COVID-19 transmission. The review also presents information about the factors modifying SARS-CoV-2 infection potential and possible local pharmacotherapeutic interventions, which may confine SARS-CoV-2 virus entry and transmission in the oral cavity. The PubMed and Scopus databases were used to search for suitable keywords such as: SARS-CoV-2, COVID-19, oral virus infection, saliva, crevicular fluid, salivary gland, tongue, oral mucosa, periodontium, gingiva, dental pulp, ACE2, TMPRSS2, Furin, diagnosis, topical treatment, vaccine and related words in relevant publications up to 28 December 2021. Data extraction and quality evaluation of the articles were performed by two reviewers, and 63 articles were included in the final review.
Highlights
This review article was designed to evaluate the existing evidence related to the molecular processes of SARS-CoV-2 infection in the oral cavity
The principal entry mechanism is initiated by binding of the spike protein (S) of the viral envelope, mainly to the SARS-CoV-2 entry factor, i.e., angiotensin-converting enzyme 2 (ACE2), which is a metallopeptidase harbored on the cell membrane
The endosomal pathway is initiated by the interaction of the SARS-CoV2 spike protein with the host cell receptor ACE2 located on the cell membrane, with subsequent endocytosis of the virus
Summary
This review article was designed to evaluate the existing evidence related to the molecular processes of SARS-CoV-2 infection in the oral cavity (the reference search protocol in provided in Supplementary Materials). In situ hybridization assays in healthy adult tissue samples from the buccal mucosa, soft palate and palatine documented increased suprabasal expression of ACE2 and TMPRSS2 compared with the basal compartment (non-keratinized) [10]. These results point to multiple sites in the oral mucosa as potentially susceptible to infection by SARS-CoV-2, which makes it prone to the infection with a possibility of viral transmission to the respiratory and gastrointestinal tract (see below). Mucosal scrapings demonstrated features of infection and replication capacity after shedding These cells can play the role of virus carriers, and promote viral stability and transmissibility
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
